Transcript Gas Exchange Summary

GAS EXCHANGE
Summary on system cards
Card No 1
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Definitions
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closely related objectives together
• For example, Gas Exchange can be
grouped into four main themes:
Gas
Gas
Gas
Gas
exchange
exchange
exchange
exchange
in general
in plants
in animals
in mammals (humans)
Gas Exchange in General
Air
Water
• 1 L contains 210 mL
of O2
• as altitude ,
density of air 
• in microenvironments, [O2]
is less and [CO2] is
greater
• greater chance of
respiratory surfaces
drying out
• 1 L contains 7 mL of
O2
• as temperature ,
salinity , or depth
, amount of gas
that can dissolve 
(including oxygen)
• less chance of
respiratory surfaces
drying out
Gas Exchange in Plants
Leaves
• stomata
• (include
diagram)
Stem
• lenticels
• (include
diagram)
Roots
•get gases from
the air spaces
in the soil
•gases diffuse
into the film of
moisture
surrounding the
root hairs
Gas Exchange in Animals
Breathing in Air
• insects have:
– tracheae, branching
tubes
– spiracles, holes in
the cuticle
• frogs exchange
gases by:
– absorbs through
skin
– gulping movements
of the throat and
floor of the mouth
Breathing in Water
• gills composed of:
– several gill arches
– gill arches contain
gill filaments
– the gill lamellae is a
section of the
filament where gas
is exchanged
• cilia can be used to
move water
• most have muscular
pump to ventilate gills